Police and youths clash in Paris May 1 march.

PARIS (AFP) - Traditional May 1 union marches turned violent in France on Monday and presidential election front runner Emmanuel Macron attacked far-right rival Marine Le Pen, highlighting the divisions six days before the runoff. Six police officers were hurt in clashes in Paris between masked youths throwing molotov cocktails and riot police who responded with tear gas, as tens of thousands of union activists took to the streets for May Day demonstrations. One riot police officer was engulfed in flames, an AFP photographer saw. Interior Minister Matthias Fekl condemned the violence and said one officer was seriously burned on the hand while another had serious burns to the face, without saying which was the officer in the photograph. Reacting to the scenes, far-right presidential candidate Le Pen tweeted: "This is the sort of mess... that I no longer want to see on our s...